1. Field of the Invention
The invention relates to a pneumatic suspension system comprising at least the following pneumatic suspension system components, specifically:
a pneumatic suspension bellows made of an elastomer material enclosing a volume-variable air chamber;
a pneumatic suspension lid to which one end of the pneumatic suspension bellows is fixed by means of a clamping ring or the like;
a pneumatic suspension piston to which the other end of the pneumatic suspension bellows is fixed by means of a clamping ring or the like as well and on whose outer wall the pneumatic suspension bellows can roll off, forming a rolling contour;
a wheel guide element;
a hinge serving as the steering means in relation to the wheel guide element; as well as
a body.
2. The Prior Art
With pneumatic suspension systems without a damper disposed on the inside, the pneumatic suspension lid is secured on the body and the pneumatic suspension piston on a wheel guide element. In the presence of spring action, the piston is then moving in relation to the lid according to the wheel guide kinematics, whereby it is not assured that the pneumatic suspension bellows rolls off on the piston in a symmetric manner.
Now a pneumatic suspension system of this type is disclosed in laid-open patent specification DE 197 04 433 A1, where the problem of relative movements between the components of the pneumatic suspension system is solved by means of an inner guide in the form of centric forced guidance. In this system, a hinge is in connection with the body and another hinge with the wheel guide element. The two hinges are connected with each other by means of the inner guide, which preferably is a guiding cylinder-and-push rod device. Since the inner guide is not intended to assume any damping properties, the pneumatic suspension system has to be separately provided with a damper. The friction occurring on the inner guide in the presence of spring action, in particular with maximum spring action to the limit of suspension, then leads to a deterioration of the pneumatic suspension system in relation to the vehicle.
Now, the problem of the invention is to provide a pneumatic suspension system without a damper disposed on the inside, in which system the wheel guide kinematics in relation to symmetric roll-off of the pneumatic suspension bellows is realized without inside guide elements influencing the comfort.
The problem is solved by the invention in that the components of the pneumatic suspension system are arranged in a such a way that only one single hinge is present within the pneumatic suspension system as the steering means in relation to the wheel guide element, with omission of centric forced guidance.
Advantageous design variations are explained in the following in greater detail.
Variation A
According to this variation, which within the framework of the concept as defined by the invention contains a particularly advantageous embodiment of the invention, the pneumatic suspension piston as the upper component is tied to the body, whereby the rolling fold of the pneumatic suspension bellows is bulging upwards. The pneumatic suspension lid as the lower component is connected with the hinge within the bottom of the lid, specifically with centric tie-up of the pneumatic suspension lid to the wheel guide element by means of the hinge.
Variation B
According to this variation, the pneumatic suspension lid as the upper component is tied to the body, whereas the pneumatic suspension piston as the lower component is connected with the hinge, whereby the hinge is located within the piston chamber and/or air chamber, specifically with centric tie-up of the pneumatic suspension piston to the wheel guide element by means of a rod extending within the piston.
Variation C
According to this variation, the pneumatic suspension lid as the upper component is tied to the body, whereas the pneumatic suspension piston as the lower component is connected with the hinge within the bottom of the piston, specifically with centric tie-up of the pneumatic suspension piston to the wheel guide element by means of the hinge. The angle of movement of the hinge is reduced in this connection in such a way that the piston is prevented from tilting in the presence of kinematic spring action.
Variation D
According to this variation, the pneumatic suspension lid as the upper component is connected with the hinge, specifically with centric tie-up of the pneumatic suspension lid to the body by means of the hinge. The pneumatic suspension piston as the lower component is centrically tied to the wheel guide element within the bottom of the piston.
Further advantageous design variations are discussed below, whereby particularly in conjunction with variation A, the pneumatic suspension system is additionally equipped with a protective bellows and/or a supporting ring.
Furthermore, it is advantageous in connection with variation A if the hinge is designed in the form of a bush-like component comprising a tubular core, a cushion made of elastomer material, and an outer sleeve.
The pneumatic suspension bellows is provided with a reinforcing insert in most cases (DE 36 43 073 A1).
Furthermore, the air chamber may be connectable via a channel with an additional air volume for increasing the comfort of the pneumatic suspension system (DE 197 04 433 A1).